Lord Alexander of Weedon, a constitutional expert and the chairman of NatWest bank, criticised Tory plans to use the party's big majority in the Lords to disrupt government Bills, including plans to strip the 750 hereditary peers of their right to sit and vote.
A Conservative Central Office briefing note, leaked to The Independent last week, revealed that the Tories were planning a "zero tolerance" policy towards "bad legislation".
But Lord Alexander said: "I thought zero tolerance was a phrase used in dealing with crime. I would be very disappointed if anything like that crept in, in the Lords fulfilling what is a very important role of evaluating where legislation could be improved."
He told GMTV's Sunday Programme that Labour's strongest argument for Lords reform was the in-built Tory majority under the present system. "That argument means there must be change," he said.
Lord Alexander warned that the Tories could "play into Labour's hands" if their peers continued to block the Bill to bring in proportional representation for next June's elections to the European Parliament.
Although he would prefer a "big bang" Lords reform which went wider than the hereditaries, he warned Mr Hague: "I think the chances of that will diminish every time that the gladiatorial contest between the Government and the House of Lords surfaces."
The European Elections Bill will be rushed through the Commons this week and Lord Alexander said that peers, who voted against it five times during the last parliamentary session, should not spend much more time on what he called "a relatively minor issue".
However, Mr Hague defended his hardline tactics over Lords reform. Interviewed on the same programme, he denied his "zero tolerance" strategy could backfire on the Tories. He insisted that Tony Blair had misjudged the public mood. "I think most people in the country think it's wrong to change the House of Lords without knowing what you're going to change it into," he said. "It fuels the suspicion that what the Prime Minister is really after is to have a House of Cronies... We just won't have an effective second chamber that is able to challenge the government of the day. Sadly, that is probably what he wants."
Buckingham Palace confirmed a report in yesterday's Independent on Sunday that the Queen has agreed that members of the Royal Family will lose their historic right to sit and vote in Parliament under the Lords reforms. The Duke of Edinburgh, Prince of Wales, and the Dukes of York, Gloucester and Kent will all lose their seats.
"Formal advice has been received from the Government on reforms and in line with established constitutional practice, the Queen has accepted that advice," a palace spokesman said.Reuse content